Countdown timer For PC,Windows and Mac (Update)

{
    "update_url": "https:\/\/clients2.google.com\/service\/update2\/crx",
    "manifest_version": 3,
    "name": "Countdown timer For PC,Windows and Mac (Update)",
    "version": "1.0",
    "description": "Simple countdown timer extension For PC",
    "permissions": [
        "notifications"
    ],
    "action": {
        "default_popup": "popup.html",
        "default_icon": {
            "16": "icon.png",
            "48": "icon.png",
            "128": "icon.png"
        }
    },
    "background": {
        "service_worker": "background.js"
    },
    "icons": {
        "16": "icon.png",
        "48": "icon.png",
        "128": "icon.png"
    }
}